Some of the $1500 stolen was to go to the Ballarat Cancer Research Centre.

Yesterday students from nine schools walked around the lake as part of Fiona's Walk, in honour of Fiona Elsey who died of cancer.

The burglary happened between Thursday night and yesterday morning when the thieves gained access to the reception area and stole the money.

Loreto College principal Judith Potter said the students had worked hard to raise the money for various charitable causes.

"We are very disappointed because some of the money taken has been raised by students for charity," she said.

"They will be very disappointed. Some of the girls were (yesterday) involved in a walk-a-thon to raise money so it was a whole range of activities they would do.

"We have been very fortunate here that (thefts) haven't been an issue, but we will review it (security)."

Ballarat Police said there were no signs of forced entry at the school. The theft was discovered when staff opened the school in the morning.

Information to Ballarat Police on 5336 6000 or Crime Stoppers on 1800 333 000.